Mogrosides are a family of triterpene glycosides isolated from fruits of Siraitia grosvenorii (Swingle), also known as Momordica grosvenori (Swingle). Extracts of the fruits are commercially used as natural sweeteners. Four major compounds, Mogroside V, Mogroside IV, Siamenoside I, and 11-Oxomogroside V, have been identified from the fruits of Siraitia grosvenorii (Swingle) that are responsible for the sweetness of the fruits (see FIG. 1). Mogroside V is the most abundant of these four compounds at approximately 0.57% (w/w) of the dry fruit, followed by Mogroside IV and Siamenoside I, each of which contain four glucose moieties. 11-Oxomogroside V has a ketone group instead of a hydroxyl at C-11. See, e.g., Takemoto, et al., Yakugaku Zasshi, 103, 1151-1154; 1155-1166; 1167-1173, (1983); Kasai, et al., Agric. Biol. Chem. 53, 3347-3349 (1989); Matsumoto, Chem. Pharm. Bull. 38, 2030-2032 (1990); and Prakash, et al., J. Carbohydrate Chem. 30, 16-26 (2011). However, the enzymes responsible for producing mogrosides have not been identified.
Tang et al. BMC Genomics 2011, 12:343 describes seven CYP450s and five UDPGs as potential candidates involved in mogroside biosynthesis. However, the document does not specifically identify any CYPs or UDPGs involved in mogroside biosynthesis.